For an integrated circuit fabrication process, some wafers have a notch for wafer alignment. For such a wafer, the wafer is rotated 360° in some cases to find the wafer notch for alignment. However, the wafer notch may result in random solvent splash on the wafer during a wafer edge cleaning process, which is a defect source and can induce yield penalty. Also, such solvent splash can induce arcing effect during an etching process of the wafer.